The present disclosure relates generally to electronic displays and, more particularly, to controlling brightness of a display backlight.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Electronic displays, such as liquid crystal displays (LCDs), are commonly used in electronic devices such as televisions, computers, and handheld devices (e.g., cellular telephones, audio and video players, gaming systems, and so forth). Such LCD devices typically provide a flat display in a relatively thin package that is suitable for use in a variety of electronic goods. In addition, such LCD devices typically use less power than comparable display technologies, making them suitable for use in battery-powered devices or in other contexts where it is desirable to minimize power usage.
LCDs typically include an LCD panel having, among other things, a liquid crystal layer and various circuitry for controlling orientation of liquid crystals within the layer to modulate an amount of light passing through the LCD panel and thereby render images on the panel. A display driver for the LCD produces images on the display by adjusting an image signal supplied to each pixel across the display. The brightness of an LCD depends on the amount of light provided by a backlight assembly. As the backlight assembly provides more light, the brightness of the LCD increases. Backlight drivers may supply driving current to the backlight assembly to illuminate the LCD at a desired brightness level. The driving current may have a constant peak value and may be modulated with a variable duty cycle, such as by using a pulse width modulated signal. Varying the duty cycle may adjust the brightness level of the backlight assembly. Unfortunately, controlling the duty cycle of the pulse width modulation signals with good linearity may be complex and may be implemented inefficiently in the LCD.